Features of the present disclosure relate to electronic devices that use an enclosure or housing, specifically a design and method for improving electromagnetic compatibility (EMC).
Electromagnetic compatibility (EMC) is the branch of electrical engineering concerned with the unintentional generation, propagation and reception of electromagnetic energy that may cause unwanted effects such as electromagnetic interference (EMI). EMI may thus cause physical damage in operational equipment. The damaging effects of EMI pose risks in many areas of technology. EMI can be mitigated to reduce the risk. The goal of EMC is the correct operation of different equipment in a common electromagnetic environment.
EMC issues include the generation of electromagnetic energy, whether deliberate or accidental, by some source and its release into the environment. The field of EMC takes into account the unwanted emissions and provides countermeasures that may be taken in order to reduce unwanted emissions. EMC issues also include the susceptibility of electrical equipment, referred to as the victim, to malfunction or break down in the presence of unwanted emissions, e.g., radio frequency interference (RFI). Immunity is the opposite of susceptibility and is the ability of equipment to function correctly in the presence of RFI. Another issue of EMI is coupling, which is the mechanism by which emitted interference reaches the victim.
Interference mitigation and electromagnetic compatibility may be achieved by addressing any of these issues, i.e., quieting the sources of interference, inhibiting coupling paths and/or hardening the potential victims. In practice, many of the engineering techniques used, such as grounding and shielding, may apply to the issues.
A standard known Industrial Personal Computer (IPC) housing 101 is illustrated in FIG. 1. As illustrated, the housing walls 111 of the IPC are extruded such that the wall structure is unitary, e.g., a closed rectangular cross-section of a single piece. Because the corners and the walls are unitary in the housing of FIG. 1, there is not a significant EMI problem. The downside of such a rectangular extruded housing part is that there is no flexibility to change the dimensions of the housing are fixed. Moreover, such unitary extruded housing can be expensive to build.
Accordingly, a housing design part to archive more competitive cost and allowing more flexibility to change size and shape was developed. The selected way to build that housing part is now corner profiles, which are installed to a base, and sheet metal walls, which slide into slots (recess) in the corner profiles. The sheet metal/corner profile assembly suffers the problem that there is a gap in between the corner profile and the sheet metal walls. This gap becomes a problem because it functions as a slot antenna, which makes it difficult to fulfil the EMC. Depending on the electronic inside, the slot antenna may remain unresolved.